#!/usr/bin/perl -w
# Copyright 2010, 2011 Kevin Ryde
# This file is part of Math-NumSeq.
#
# Math-NumSeq is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 3, or (at your option) any later
# version.
#
# Math-NumSeq is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
use 5.004;
use strict;
use List::Util 'max';
{
# long cycles
foreach my $radix (2 .. 200) {
my $max_steps = 0;
my @max_seen;
foreach my $start (2 .. 100) {
my $steps = 0;
my %seen;
my @seen = ($start);
my $i = $start;
for (;;) {
my $sum = 0;
while ($i) {
my $digit = ($i % $radix);
$sum += $digit * $digit;
$i = int($i/$radix);
}
$i = $sum;
push @seen, $i;
$steps++;
if ($i == $start) {
if ($steps > $max_steps) {
$max_steps = $steps;
@max_seen = @seen;
}
last;
}
if ($seen{$i}) {
last;
}
$seen{$i} = 1;
}
}
print "$radix $max_steps ",join(',',@max_seen),"\n";
}
exit 0;
}